The present invention relates to a method and apparatus for processing dermal tissue that has been harvested from a patient and, in particular, relates to a method and apparatus for cutting and mincing dermal tissue into particles suitable for transplantation into a wound on the patient.
Skin grafting has traditionally involved the removal of a thin slice of dermal tissue from a donor site on a patient. The slice of tissue is then used to cover the site of a wound, which is typically a non self-healing wound or a burn. In some cases the tissue is processed before it is applied to the recipient wound site. A common process called meshing creates a number of small, non-connected cuts in the slice of tissue. The tissue can then be stretched until it has the appearance of a mesh or net. In this state, it can cover a larger area of a wound. Other methods of processing include cutting the tissue into particles with knives, blades or scissors.
The purpose of such processing is to use tissue from a donor site to cover a wound area that is larger than the donor site. The ratio of the wound area to the donor site area is called the expansion ratio. A higher expansion ratio is desirable to minimize the trauma of the donor site, and to aid patients who have only a small amount of dermal tissue available for grafting purposes.
Traditional methods of processing dermal tissue have produced low expansion ratios. They have also produced poor cosmetic outcomes in which the healed wound exhibits a rough and uneven surface.
Another device utilizes a drum carrying a plurality of parallel blades that is supported above a cutting surface. A strip of tissue is placed on the cutting surface, and the device is activated to rotate the drum and bring the blades into contact with the underlying cutting surface. The tissue is manually translated across the cutting surface to enable the blade to slice the tissue into fine strips. The strips of tissue can then be repositioned on the cutting surface to enable the blades to cut the strips into individual particles. Unfortunately, particles may accumulate in the interstices between adjacent blades and need to be manually removed using a spatula or the like. Furthermore, because the position of the blade is stationary relative to the cutting surface, the cutting operations may be rigid and difficult to perform.
It would therefore be desirable to provide a simpler processing device that is inexpensive, disposable and easy to use compared to conventional devices. It would be further desirable to achieve higher expansion ratios than conventionally achieved in order to improve cosmetic outcomes for healed wounds.